Production of stabilized forage crops



Patented Sept. 23, 1952 PRODUCTION OF STABILIZED FORAGE I 1 CROPS v Chester Ray Thompson, Richmond, Calif; as-

. signor to the United States of America as rep-j resented by the Secretary of Agriculture No Drawing. Application April 28, 1950, Serial N0. 158,905

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 22 Claims.

This application is made under the act of March 3, 1883, as amended by the act of April 30, 1928, and the invention herein described, if patented in any country, may be manufactured and used by or for the Government of the United States of America for governmental purposes throughout the world without the payment to me of any royalty thereon.

This application is a continuation-in-part of my copending application for patent Serial No. 113,243, filed August 30, 1949, now abandonedentitled Stabilization of Alfalfa.

This invention relates to the preservation of forage crops. In particular, the invention relates to the treatment of dried forage crops, such as dried grasses, legumes, and especially alfalfa, so as to stabilize the carotene content of the forage material.

The problem with which this invention is concerned may be illustrated by the following reference to alfalfa:

Alfalfa is widely used as a feed and as an ingredient in mixed feeds for chickens, cattle, and other livestock. It is especially valuable for such. purposes because of its high carotene content. Generally, alfalfa is used in the form of a meal prepared by harvesting fresh alfalfa, drying it andcomminuting the dried alfalato ameal. In this form the alfalfa will not spoil and can be readily bagged for storage or shipping. One problem that has beset the industry, however, is that upon storage certain chemical changes take place whereby the carotene content is rapidly decreased. For example if the meal is stored at 80 F., it loses about two-thirds of its carotene content in 24 weeks. Of course at higher temperatures such as prevail in barns or warehouses in summer, the rate of carotene loss is greatly accelerated.

' It has now been found that the carotene content of alfalfa or other forage crop is stabilized if a di(hydrocarb'on) -substituted hydroquinone, particularly a 2,5-di(hydrocarbon)-substituted hydroquinone, is incorporated therewith. The hydroquinone derivatives which may be used in accordance with this invention are represented by the following formula:

wherein R and R represent the same, or dissimilar, hydrocarbon radicals, as for'example,

methyl, ethyl, propyl, isopropyl, n-butyl, secbutyl, isobutyl, tert-butyl, n-amyl,;isoamyl, tertamyl, sec-n-amyl, sec-isoamyl, plienyl, "b enz yl, cyclohexyl, and so forth. In, general, I prefer to use the following compounds as having especially desirable stabilizing power: 1

C(CHs): I

(CHx):C

OH 2,5-ditertiarybutyl hydroquinone X 92 came 2 5 2,5-ditertiaryamyl hydroquinone' CH2-CGH6 CuHs-CHi- 2,5-dibenzyl hydroquinone Only a small amount of the above-described agents are-required to obtainv the stabilizing ef-v feet, 1. e., from about 0.01% to about 0.5% based on the amount of forage material. The agents are generally applied to the forage in theform of a solution or an emulsion so that the small proportion of this material canbe applied uni-.- formly. Suitable solvents are, for example, ethylene glycol monoethyl ether, deodorized kerosene, ethanol, n-propanol, iso-propanol, nbutanol, propylene glycol, and glyceride oils such as cottonseed oil, soybean oil, coconut oil, corn oil, peanut oil, sesameoil, and so forth Glyceride oils, especially crude vegetable oils are preferred solvents as they reduce dustincss of the dehydrated forage and further in some cases, alfalfa, for example, they give it an enhanced green color. In using a glyceride oil as the solvent it is preferred to first dissolve the stabilizing agent in a small amount of acetone and then mix this solution with the oil. In this way solution of the stabilizing agent is more readily attained. Generally, the beneficial effect of the glyceride oil is attained when applied in a pro-.- portion of from about 0.5 to about 5 based on the amount of forage. In preparing the emulsion form of the stabilizing agent, a solutlon'of the stabilizing agent in any of the aforementioned polyglyceride of a glyptal resin, and so forth."

The concentration of the stabilizing agent in the solution or emulsion is not critical, generally for convenience a liquid prepar ation containing about 5 to of the stabilizing agent is used.

The most convenient methodofrapplying. the.

solution or emulsion of the stabilizing agent is to spray it onto the forage. To secure uniform impregnation, the forage is preferably agitated by suitable means during the spra3zins to expose all surfaces thereof to the spray. Thus one; practical method involves tumbling the forage about his, rotating drum. while the solution. Or. emulsion isspra-yed. into the interior; ofthedrum; Another method involves: allowing the forage to; fall thrpugha tower equipped withbafiles ;while it, is sprayedwith, the solution or emulsion on its pas sage through the tower. It isevident that any other apparatus or method which is adapted to obtain uniform impregnation can be used. The solution or emulsion of the stabilizing agent can be applied to the green forage, to the finished dehydrated forage, onitcan be applied to the forage at various stages in its processing. Thus for example, the solutioncan be. applied to the forage after it is dehydrated but before it is comminuted to form a-meal. Further, the solution can be applied. while the dehydrated forage is being milled to produce the meal.

The following examples disclose steps and conditions within the scope of this invention. It is understood that these; examples are furnished only by way of illustration. and not limitation.

A 200 gram sample of dehydrated alfalfa meal was placed in a cylinder, provided with bafiles. While rotating the cylinder to cause thorough agitation of the meaLthemealwas sprayed with 4 ml. of an ethylene glycolmonoethyl ether solution. containing 0.24 gram: of .2,5.-.ditertiarybutyl hydroquinone. The; treated meal. therefore containedw0. 125?% of ;2,5'f-ditertiarybutyl. ihydroqui'e none...

Samples :of: the treated mea-llanda sample of theuntreated-meal- (control) were stored in open vesselsratfifi C: and the caroten content of each samplewasdetermined after storage: for -5: days and' lfl days at this temperature. The carotene contentsaafter storage .were compared with" the original carotene content of the: meal to determine the proportion-oforiginal carotene remain mg the mealafter storage- The following results-wereobtainedz--- (ill Samples of the treated meal and a sample of the untreated meal (control) were stored in open vessels at 25 C. and theocarotene content of each sample :was determined after storage for 4 weeks and'B'weeks at this temperature. The carotene contents after storage were compared with the original carotene of the meal to determinethe proportion of original carotene remaining in the meal after storage. The following resuits were obtained:

Samples-:ofdehydrated alfalfa meal were sprayed" with an ethylene glycol monoethyl other solution of 2,5-ditertiarybutyl .hydroquinone-i'n the same 'manner'as set forth in Example-I. In one case, 0.125% of 2,5'-ditertiarybutyl' hydroquinone was added; in-- another case- 0.-25%- of 2,5-ditertiarybutylhydroquinonewas-= added. Samples, of the treated meal and a sample of the untreated meal- (control) were stored at-- C: in-open vessels and -the carotene-content of each sample was determined after storage for '7 and--14 days at this temperature; The carotene contents after storage were compared withthe original-content of the meal to determine' the proportionof original carotene remaining irr the meal after storage. The following results were obtained: I

Tablez Sample- Proportion of original carotene remaining.

in meal after" storageat 65 C.

Proportion of original .caro'.-. .teneremainlng.

inmeal'aiter storageat 65? CC. for ladoys percent Untreated sample (control).

Treated sample (0.125% 2.5- ditera;

A, series of 200 gram samples of dehydrated alfalfa meal were each treated with a solution of 2,5.-'ditertiarybutyl. hydroquinone a's' setf'orth in Example'I. In" eachlcase. the solution con-'- tained 0.25 gram of zg5-ditertiarybutylhydroqui none and was made toa volume of 4ml. withithe particular solvent as indicated hereinafter." In

each case the treated sample contained. 012598 of 2,5-ditertiarybutyl hydroquinon'e. An untreatzi ed sample (control) and the treated samples were then stored at 65 C'. in open vessels and then analyzed for carotenewcontent. The carotene contents after storage-were compared with the original carotene content of the meal to determine the proportion-of original carotene remaining. in. the. .meal. aften..stor;age;' Theufo'llowing .resul s werewobtameda: 111m A series of 200. ram samples. of dehydrated alfalfa meal were each'. treated with a. solution of 2,5-ditertiarybutyl. hydroquinone as set forth. in Example I. In eachcase, the solution contained 0.25 gram of 2,5-ditertiarybutyl hydroquinone and was made up to. avolume' of 2.6 'ml. with acetone after which they were made to a volume of 4 ml'. with the particular solvent indicated hereinafter.- In each. case, the treated sample contained 01125%I o'f 2',5-ditertiarybutyl hydroquinone. Anuntreated sample (control) and'the treated samples were. stored at. 65C. in open vessels and thenanal'yzedflfor carotene content. The carotenecontents after storage were comparediwith the original carotene content of the meal to determine the proportion of original carotene remaining in. the meal-after storage. The following results-were obtained: I

. Table 4 Proportion of Proportion of Proportion of ongmal carooriginal. caro- 2,5-ditert1a'- v tene remaining tene remaining rybutyl hy- Solvent in meal-after; in meal afterdroquinone,, storage'at 65 storage at 65 I percent 0. for 7.days, C..for 14. days,

- percent percent I crude cottonseed 82 67 crude'soybean oil.. I 78 61 refined coconut oil 80 66 refined peanut oil.. 85 68 sesame oil 74- 66 odorless kerosene 77 63 A 'ZOO-gram sample of dehydrated alfalfa meal was placed in a rotatable cylinder'provided with baflles. While rotating the cylinder to cause thorough agitation of the meal, the meal was sprayed with 4 ml. of an ethylene glycol monoethyl ether solution containing 0.25 gram of 2,5- ditertiaryamyl hydroquinone. The treated meal therefore contained 0.125% of 2,5-ditertiaryamyl hydroquinone.

Samples of the treated meal and a sample of the untreated meal (control) wer stored in open vessels at 65 C. and the carotene content of each sample was determined after storage for 14 days at this temperature. The carotene contents after storage were compared with the original carotene content of themeal to determine the proportion of carotene remaining in the meal after storage. The following results were obtained:

6 Table 5 Proportion oforlginal caro- Sample Untreated sample (control) '23 Treated sample (0.125% 2,5-d yamyl yd a quinone) w 58 EXAMPLE VI A. series of ZOO-gram samples of dehydrated alfalfa meal were each treated with a 1%s'olution of 2,5-ditertiaryamyl hydroquinone in crude cottonseed oil using the same technique as set forth in Example V. In each case the amount of solution used was varied so that the respective samples contained varying amounts of 2,5-ditertiaryamyl hydroquinone.

An untreated sample (control) and the treated samples were then stored at 65 C. in open vessels and then analyzed for carotene content. The carotene contents after storage were compared with the original carotene content of the meal todetermine the proportion of original carotene remaining in the meal after storage. The following results were obtained: i

tene remaining Table 6 (Proportion or g gof original carotene 4 itertiaryremaim-n in Experiment No. amylhydro- 'mealraftersamge p d y pe cen none (control) 1 I 23 A ZOO-gram sample ofdehydrated alfalfa meal was sprayed with anethylene glycolmonoethyl ether solution of 2",5=dibenzy1 hydroquin'one using the technique set forthin Example I. v'Ilie'trea t ed meal contained 0.125% "of 2,5'-dibenzylhydroquinone. v t

An untreated sample (control) and the reated sample were then stored at 65 Crinopen-vessels and then analyzedfor caroten contentf- The carotene contents after st'orage werecompared withythe original carotene contentof themealto determine the proportion oforig-inal carotene re maining in the meal-"after storage; The iollo'w in result's were obtained: Table 7 Proportion of original carotene remaining in meal after storage at 65 C. for 14 days, percent Sample Untreated sample (control) Treated sample (0.125% 2,5-dibenzyl hydroquinone) 46 nism of the stabilization is not known although 7 the foregoing data indicate that the agents act as negative catalysts in preventing oxidation of the carotene.

The powerful stabilizing effect of these compounds in this respect is surprising because many known anti-oxidants have little if any effects on the stabilization of carotene. This fact is shown by the following experiments:

' A series of 200-gram samples of dehydrated alfalfa meal were each treated with a solution of a known anti-oxidant using the spray technique set forth in Example I. In each case, the solution contained 0.25 gram of the anti-oxidant and was made up to a volume of 4 ml. with ethylene glycol monoethyl ether. In each case the treated meal contained 0.125% of the anti-oxidant. An untreated sample (control) and the treated samples were stored at 65 C. in open vessels and then analyzed for carotene content. The carotene contents after storage were compared with the original carotene content of the meal to determine the proportion of original carotene remaining in the meal after storage. The following re sults were obtained:

Proportion of original carotene remaining Proportion of original carotene remaining which comprises incorporating in meal after storage at 65 C. for 10 days, percent Anti-oxidant in meal after storage at 65 C. for 14 days, percent none used (control) nordihydroguaiaretic acid thiodipropionic acid". lauryl thiodipropionat 'pyrogallol hydroquinone mono methyl ether p-tertiary butyl catechol. di henylamine 'et yl hydrocaffeate 2,4-dimethyl-6-tertiarybutyl phenol a forage crop therewith 2,5-

a forage crop therewith 2,5- dibenzyl hydroquinone.

5. The process in accordance with claim 1 wherein the forage crop is dehydrated alfalfa. 6. The process in accordance with claim 2 wherein the forage crop is dehydrated alfalfa. '7. The process in accordance with claim 3 wherein 8 wherein the forage crop is dehydrated alfalfa.

8. The process in accordance with claim 4 wherein the forage crop is dehydrated alfalfa.

9. The process of stabilizing dehydrated alfalfa which comprises spraying an agitated mass of dehydrated alfalfa with a solution of 2,5- ditertiarybutyl hydroquinone.

10. The process of stabilizing dehydrated alfalfa which comprises spraying an agitated mass. of dehydrated alfalfa with a solution of 2,5-ditertiaryamyl hydroquinone.

11. The process of stabilizing dehydrated alfalfa which comprises spraying an agitated mass of dehydrated alfalfa with a solution of 2,5- dibenzyl hydroquinone.

12. A stabilized forage product comprising a forage crop having incorporated therewith a. 2,5- di(hydrocarbon) -substituted hydroquinone.

13. A stabilized forage product comprising a forage crop having incorporated therewith 2,5- ditertiarybutyl hydroquinone.

14. A stabilized forage product comprising a forage crop having incorporated therewith 2,5- ditertiaryamyl h-ydroquinone.

15. A stabilized forage product comprising a forage crop having incorporated therewith 2,5- dibenzyl hydroquinone.

" 16. A .product: in accordance with claim 12 wherein the forage crop is dehydrated alfalfa. 17. A product, in accordance with claim 13 wherein the forage crop is dehydrated alfalfa.

18. A product in accordance with claim 14 wherein the forage crop. isdehydrated alfalfa.

19. Aproduct in accordance with claim 15 the forage crop is dehydrated alfalfa.

20. A stabilized I dehydrated alfalfa product comprising dehydrated alfalfa and from about 0.01% to about 0.5% of 2,5-ditertiarybutyl hydroquinone incorporated therewith.

21. A stabilized dehydrated alfalfa product comprising dehydrated alfalfa and from about 0.01% to about 0.5% of 2.5-ditertiaryamyl hydroquinone incorporated therewith.

22. A stabilized dehydrated alfalfa product comprising dehydrated alfalfa and from 0.01% to about 0.5% of 2,5-dibenzyl hydroquinone incorporated therewith.

CHESTER RAY THOMPSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES lPATENTS Number Name Date 2,226,177 Orelup Dec. 24, 1940 2,474.182 Kephart June 21. 1949 

1. THE PROCESS OF STABILIZING A FORAGE CROP WHICH COMPRISES INCORPORATING THEREWITH A 2,5DI(HYDROCARBON) SUBSTITUTED HYDROQUINONE. 